314 
Mycologia 
be called ferax, while those with weak mycelium and with 
anther idia on one half or more of the oogonia belong to S. mixta 
as described by de Bary. 
This merely recognizes the fact that this species is a complex 
of forms of which de Bary happened to find one, and in this 
form the loss of sexuality had gone further than in most of the 
members of the complex. 
University of Michigan, 
Ann Arbor, Mich. 
LITERATURE CITED 
Nees von Esenbeck, C. G., ’23. Zusatz to a paper by Carus, C. E., Beitrage 
zur Geschichte der unter Wasser an verwesenden Thierkorpen sich er- 
zeugenden Schimmel — oder Algengattungen. Nova Acta Acad. C. L. C. 
N. C., Bd. XI, Th. II, 1823. (Taken from Humphrey, q. v.) 
Bary, A. de, ’52. Beitrag zur Kenntniss der Achlya prolifera. Bot. Zeit., 
Bd. X, p. 473, and T. VII, 1852. 
, ’81. Untersuchungen iiber Peronosporeen and Saprolegnieen 
Beitr. zur Morph, und Phys. der Pilze, IV, Reihe 1881. 
, ’88. Species der Saprolegnieen. Bot. Zeit., Bd. XLVI, pp. 
613, 1888. 
Thuret, G., ’50. Recherches zur les Zoospores des Alguez et les Antheridies 
des Cryptogams. Ann. Sci. Nat. Bot., 3rd Ser., T. XIV, p. 214, 1850. 
Pringsheim, N., ’57. Beitrage zur Morphologic und Systmatic der Algen. 
II. De Saprolegnieen. Jarb. fiir wiss. Botanik, 3d I, 1857. 
> ’73- Weitere Nachtrage zur Morphologic der Saprolegnieen. 
Jahrb. fiir wiss. Bot., Bd. IX, p. 191, 1873-74. 
Humphrey, James E., ’92. The Saprolegniaceae of the United States. Pro- 
ceedings of the Amer. Phil. Soc. 1892. 
Klebs, G., ’99. Zur Physiologic der Fortpflanzung eniger Pilze, II, Jahrb. fur 
wiss. Botanik, 33, p. 513, 1899. 
Kauffman, C. H., ’08. A contribution of the Physiology of the Saprolegni- 
aceae. Annals of Bot., Vol. XXII, July, 1908. 
Explanation of Plate CLXX 
Fig. I. Saprolegnia ferax (Gruith.) Thuret from fly culture in cool window 
of number 25 ; showing oogonia with androgynous and diclinous antheridia. 
X 167. 
Fig. 2. Oogonium of 5 '. monoica Pringsh. showing androgynous and 
diclinous antheridia on the same oogonium. X 440. 
